Abstract
Aim
The surgical success rate of tympanoplasty appears to be influenced by a number of variables. Eustachian tube dysfunction has been shown as one of the factors causing failure in tympanoplasty. It is known that bilateral disease and decreased in mastoid pneumatization are associated with Eustachian tube (ET) dysfunction. In this study, the relationship between the success of type 1 tympanoplasty and mastoid pneumatization, bilateral disease and ET function was investigated.
Materials and Methods
A total of 44 patients who were operated for chronic otitis media in our clinic were included. The information of the patients was obtained retrospectively, the direction of the disease (bilateral/unilateral), the status of the graft (intact/perforated), mastoid pneumatization status, and hearing levels (preoperative/postoperative 6th month) were noted. Automatic Williams test was used to tympanometrically evaluate ET functions (ETF) in postoperative period. The relationship between tympanoplasty success and mastoid pneumatization, bilateral disease and ETF was investigated by statistical analysis.
Results
The disease aspect was found bilateral in 34.1% (n = 15) of the cases, and unilateral in 65.9% (n = 29) of the cases. Mastoid pneumatization was decreased in 52.2% (n = 23) of the cases, and normal in 45.4% (n = 20). The preoperative air-bone mean difference (gap) of the cases with decreased mastoid pneumatization was found to be statistically significantly higher than the cases with normal mastoid pneumatization (p < 0.05). The closure of the postoperative air-bone gap in patients with unilateral disease direction was found to be statistically significantly higher than in patients with bilateral disease direction (p < 0.05). Also we found significantly worse ET functions both in unilateral and bilateral disease.
Conclusion
Preoperative air-bone gap average is higher in ears with decreased mastoid pneumatization, and postoperative air-bone gap closure is higher in unilateral patients. Mastoid ventilation does not make a significant difference in the success of type 1 tympanoplasty. On the other hand, our results support that ET dysfunction can be effective in the occurrence of chronic otitis media (COM).
Keywords: Bilateral, Eustachian tube, Mastoid, Tympanoplasty, Pneumatization
Introduction
Chronic otitis media (COM) is a chronic infection and inflammation of the middle ear and mastoid, often manifested clinically by discharge and hearing loss. COM usually occurs as a result of recurrent acute otitis attacks or otitis media with chronic effusion [1]. In COM cases, there are medical and/or surgical treatment options depending on the stage of the disease. The primary goal of treatment is eradication of the infection and the secondary goal is restoration of hearing [2].
There are numerous and various factors that affect the success of surgery in tympanoplasty, such as type of graft and approach, clearance of disease, condition of middle ear mucosa, eustachian tube functions, middle ear ventilation, nasal pathologies (septal deviation, concha hypertrophy, nasal polyps etc.), some comorbid systemic diseases. Of all these factors, the condition of the middle ear ventilation is an important factor affecting surgical success; and the function of the eustachian tube, the degree of pneumatization of the mastoid air cells, and the condition of the mucosa of the middle ear affect the ventilation of the middle ear [1–4].
It is known that the degree of mastoid pneumatization is closely related to eustachian tube function and mastoid pneumatization is poor in most cases of chronic otitis media and cholesteatoma [3, 4]. Two theories of mastoid pneumatization are accepted. According to the genetic theory; the prevalence of mastoid pneumatization is determined genetically and its variations constitute anatomical and etiological factors for chronic otitis media. According to the environmental theory, environmental factors determine the prevalence of mastoid pneumatization. According to this theory, childhood diseases affect the mastoid pneumatization process and cause sclerotic mastoid formation [5].
Numerous research in the literature have supported that dysfunction of the ET has a role in a vital part in the etiology of COM [6]. The main functioning of the ET are equalizing the pressure, facilitating the mucociliary clearance of secretions, and shielding the middle ear [7]. When ET does not work properly, negative pressure in the middle ear accumulates, causing the eardrum to retract and eventually resulting in COM [7]. One indirect indicator of ETF is the extent of mastoid pneumatization. In addition to mastoid ventilation, bilateral disease is also thought to be related to eustachian tube dysfunction.
Another question is whether surgical success (graft success and hearing results) can be achieved with type 1 tympanoplasty in cases with mastoid sclerotic and without cholesteatoma at the same rate as in cases with well-ventilated mastoid. Although there are few studies in the literature on the relationship between middle ear ventilation and tympanoplasty, but there is no study examining relationship between mastoid pneumatization and type 1 tympanoplasty with temporal facia graft. In this study, we aimed and investigated the relationship between the effect of mastoid pneumatization, bilateral involvement and ET function and graft success in type 1 tympanoplasty. Therefore, our study is a preliminary study and we think that it will contribute to the literature.
Materials and Methods
This study was approved by the local ethics committee with the decision numbered 2016/21 and was conducted in accordance with the 2008 principles of the Declaration of Helsinki.
Before the start the study, power analysis was performed. G∗Power (v3.1.7) program was used and statistical analysis showed that there must be at least 30 patients in the study to get 80% power at the level of α = 0.05. In the study, type 1 tympanoplasty was performed due to chronic otitis media between January 2015 and December 2016 in our clinic; a total of 44 patients, 20 male and 24 female, were included.
Examination findings including the preoperative evaluation and postoperative follow-up results of the patients, temporal bone computed tomography (CT) and pure tone audiometry results were obtained retrospectively from the hospital system and the files of the patients. The direction of the disease (bilateral/unilateral), graft status (intact/perforated), mastoid pneumatization status (normal/decreased), and hearing levels were noted. Temporal bone computed tomography results within 1 month preoperatively were used to evaluate mastoid pneumatization (Figs. 1 and 2), and preoperative and postoperative 6 month pure tone audiometry results were used to evaluate hearing levels. The relationship between tympanoplasty success (graft success, air-bone gap, hearing gain) and mastoid pneumatization and bilateral disease was investigated by statistical analysis methods.
Fig. 1.
The temporal bone computed tomography image of the patient whose mastoid aeration was evaluated as normal. Red arrow; indicates the cells with normal mastoid ventilation
Fig. 2.
The temporal bone computed tomography image of the patient who was evaluated as having decreased mastoid aeration. Blue arrow; indicates the cells with decreased mastoid ventilation
The classifcation system determined by Han et al. [8] was used to determine the degree of mastoid pneumotization. In the axial section, where the malleoincudal complex looks like an ice cream cone, three parallel lines were drawn in an anterolateral direction at an angle of 45°, each intersects the most anterior point of the sigmoid sinus (SS) at its junction with the petrous bone, the most lateral aspect along the transverse plane of the sigmoid groove, and the most common posterior point of the sigmoid sinus, respectively. These lines allowed for the classification of the degree of mastoid pneumatization into four categories (Fig. 3a-d):
Fig. 3.
On the axial section where the malleoincudal complicated (blue arrow) seemed as an ice- cream-cone shape. Three parallel lines (orange lines) attracted angled at 45° to the anteroposterior axis (red line). a hypo-pneumatization, b moderate pneumatization, c good pneumatization, d hyper- pneumatization (navy blue arrow indicates sigmoid sinus)
Hypo-pneumatization, refers to pneumatization that extends to the line drawn at the SS’s most anterior aspect (Fig. 3a).
Moderate pneumatization, refers to pneumatization that extends to the area between the arbitrary lines at the sigmoid sinus most anterior point and lateral aspect (Fig. 3b).
Good pneumatization, the area between the lines drawn at the most lateral region and the most posterior point of the SS must also be pneumatized (Fig. 3c).
Hyper-pneumatization, is defined as pneumatization that extends postero-laterally over the sigmoid sinus posterior terminus (Fig. 3d).
In our study, according to Han’s classification [8], we considered hypo pneumatization as decreased, moderate and good pneumatization as normal and hyper pneumatization as increased. We also measured mastoid volumes. In volumetric procedure, CT imaging identified mastoid air cells with a level of gray scale similar to air in the temporal bone. After imaging processing, only the volumes of the extracted pneumatized parts were measured. Images were standardized for all patients by taking similar times of basal turn of cochlea, internal acoustic canal and ossicular chain of affected ears in coronal slices and calculated. There is no pathological finding in temporal bone slices in all patients.
The patient’s medical history, physical examination findings and imaging examinations were examined in the files of the patients. After the patient files were reviewed retrospectively; patients who had santral perforations, intact middle ear mucosa, no signs of clinical or radiological infection, no cholesteatoma, no ossicular chain pathology with intact and mobile ossicular chain and no previous ear surgery were included the study. In addition, patients who were followed up at 1 week, 1 month, 3 months, and 6 months were included in the study. Patients who had septum deviation, nasal congestion/polyposis, symptoms of allergic rhinitis or adenoid lymphoid tissue at nasopharynx, who had marginal or total perforations, cases with chronic otitis media who had cholesteatoma and underwent mastoidectomy, ossicular reconstruction, or cholesteatoma surgery and patients who did not come to their regular check-ups for 6 months in the postoperative period were excluded from the study. Also those with additional comorbid diseases other than existing ear disease and were younger than 13 years of age were not included in the study.
All patients were operated via retroauricular approach with over-under technique and temporal muscle fascia was used as graft in all patients (Microscopic type 1 tympanoplasty with temporal facia graft; A posturicular incision exposed the temporal muscle fascia and was then removed for temporal fascia grafting. The edges of the tympanic membrane perforation was de-epithelialized. The middle ear was exposed when tympanomeatal flap was elevated following external ear canal incisions. Then epithelial remnants removed from manubrium mallei. Using an over-under technique, the temporalis fascia was positioned over the lateral process and manubrium mallei and beneath the tympanomeatal flap. The graft was supported medially and laterally with absorbable gelatin sponge).
The patients were called for control and tympanometry (MAICO touchTymp MI 36, Berlin, Germany) was used to examine the Eustachian tube function. Williams test was used to automatically evaluate tube function in patients (ETF). Tympanometry was used to measure the baseline middle ear pressure (P1) at rest, the Toynbee maneuver (P2), and the Valsalva maneuver (P3). Normal function was defined as a difference between Pmax and Pmin of more than 15 daPa and a pressure difference between P1 and P2 of more than 10 daPa.
Results
The study was conducted with a total of 44 subjects, 45.4% (n = 20) male and 54.6% (n = 24) female. The ages of the cases ranged from 15 to 62 years, with a mean of 33.7 ± 14.2 years. The findings obtained as a result of the evaluation of the data obtained from the study with statistical methods are presented in Tables 1, 2, 3, 4, 5, 6 and 7.
Table 1.
Findings on Demographic Characteristics
| N = 44 | Min-Max | Mean ± SD | |
|---|---|---|---|
| Preop Audiogram Airway | 18–62 | 35.76 ± 11.42 | |
| Preop Audiogram Bone Conduction | 3–33 | 11.74 ± 6.03 | |
| Preop Audiogram Gap | 5–41 | 24.98 ± 8.73 | |
| Postop Audiogram Airway | 5–60 | 21.89 ± 14.24 | |
| Postop Audiogram Bone Conduction | 0–28 | 9.83 ± 6.21 | |
| Postop Audiogram Gap | 0–40 | 12.58 ± 11.21 | |
| n | % | ||
| Direction of the Disease | Bilateral | 15 | 34.1 |
| Unilateral | 29 | 65.9 | |
| Operation | Right Tympanoplasty | 21 | 47.7 |
| Left Tympanoplasty | 23 | 52.3 | |
| Graft | Intact | 42 | 95.5 |
| Perforated | 2 | 4.5 | |
| Mastoid Ventilation | Decreased | 23 | 52.2 |
| Normal | 20 | 45.4 | |
| Increased | 1 | 2.4 | |
Table 2.
Distribution of Mastoid Aeration
| Groups | P | |||||
|---|---|---|---|---|---|---|
| Decreased | Normal | Increased | Total | |||
|
Mastoid Volume (cm3) |
n Aver ± SD |
23 5.53 ± 1.94 |
20 5.68 ± 1.52 |
1 6.01 ± 1.98 |
44 5.83 ± 1.81 |
0.497 |
Table 3.
Evaluation of Preop and Postop Gap, Airway and Bone Conduction Measurements According to Mastoid Pneumatization
| Mastoid Pneumatization | p | |||||
|---|---|---|---|---|---|---|
| n | Normal | n | Decreased | |||
| Preop Gap | Mean ± SD | 20 | 21.83 ± 7.02 | 23 | 26.98 ± 9.76 | a 0.042* |
| Min-Max (Median) | 7–35 (20) | 5–41 (28) | ||||
| Postop Gap | Mean ± SD | 20 | 11.87 ± 10.21 | 23 | 12.79 ± 11.68 | a 0.718 |
| Min-Max (Median) | 3–40 (8) | 0–36 (8) | ||||
| Preop Airway | Mean ± SD | 20 | 33.23 ± 11.01 | 23 | 39.08 ± 11.31 | a 0.083 |
| Min-Max (Median) | 20–63 (33) | 17–58 (41) | ||||
| Postop Airway | Mean ± SD | 20 | 21.93 ± 14.21 | 23 | 22.61 ± 14.67 | a 0.981 |
| Min-Max (Median) | 5–60 (17.5) | 5–48 (18) | ||||
| Preop Bone Conduction | Mean ± SD | 20 | 11.78 ± 7.21 | 23 | 11.67 ± 4.99 | a 0.721 |
| Min-Max (Median) | 3–33 (10) | 5–25 (10) | ||||
| Postop Bone Conduction | Mean ± SD | 20 | 9.81 ± 6.62 | 23 | 8.83 ± 5.37 | a 0.513 |
| Min-Max (Median) | 0–28 (10) | 5–23 (8) | ||||
a Mann Whitney U Test *p < 0.05
Table 4.
Evaluation of Preop and Postop Gap, Airway and Bone Conduction Measurements According to Mastoid Pneumatization
| Mastoid Pneumatization | p | |||||
|---|---|---|---|---|---|---|
| n | Normal | n | Decreased | |||
| Airway Hearing Gain | Mean ± SD | 20 | 11.61 ± 9.18 | 23 | 17.02 ± 11.92 | a 0.228 |
| Min-Max (Median) | -13-31 (12.0) | 0–43 (13.5) | ||||
| Bone Conduction Hearing Acquisition | Mean ± SD | 20 | 1.80 ± 5.36 | 23 | 2.85 ± 3.73 | a 0.546 |
| Min-Max (Median) | -8-15 (2.0) | -4-10 (2.0) | ||||
| Gap Hearing Gain | Mean ± SD | 20 | 10.1 ± 8.95 | 23 | 15.3 ± 10.72 | a 0.114 |
| Min-Max (Median) | -12-28 (11.0) | -5-36 (14.0) | ||||
a Mann Whitney U Test
Table 5.
Evaluation of Preoperative and Postop Gap, Airway and Bone Conduction Measurements According to the Direction of the Disease
| The Direction of the Disease | p | |||||
|---|---|---|---|---|---|---|
| n | Unilateral | n | Bilateral | |||
| Preop Gap | Mean ± SD | 29 | 25.69 ± 8.63 | 15 | 23.87 ± 9.42 | a 0.461 |
| Min-Max (Median) | 7–41 (23) | 5–40 (24) | ||||
| Postop Gap | Mean ± SD | 29 | 10.49 ± 8.63 | 15 | 16.1 ± 13.21 | a 0.151 |
| Min-Max (Median) | 0–33 (7) | 2–40 (11) | ||||
| Preop Airway | Mean ± SD | 29 | 37.33 ± 11.12 | 15 | 36 ± 11.81 | a 0.857 |
| Min-Max (Median) | 20–63 (37) | 17–50 (38) | ||||
| Postop Airway | Mean ± SD | 29 | 20.82 ± 12.82 | 15 | 25.89 ± 16.03 | a 0.318 |
| Min-Max (Median) | 5–60 (17) | 5–58 (20) | ||||
| Preop Bone Conduction | Mean ± SD | 29 | 11.67 ± 6.43 | 15 | 12.17 ± 5.45 | a 0.542 |
| Min-Max (Median) | 3–33 (10) | 5–25 (11) | ||||
| Postop Bone Conduction | Mean ± SD | 29 | 9.72 ± 6.38 | 15 | 9.72 ± 5.88 | a 0.568 |
| Min-Max (Median) | 3–28 (8) | 0–22 (10) | ||||
a Mann Whitney U Test
Table 6.
Evaluation of Preoperative and Postop Gap, Airway and Bone Conduction Measurements According to the Direction of the Disease
| The Direction of the Disease | p | |||||
|---|---|---|---|---|---|---|
| n | Unilateral | n | Bilateral | |||
| Airway Hearing Gain | Mean ± SD | 29 | 16.15 ± 11.16 | 15 | 10.97 ± 9.72 | a 0.263 |
| Min-Max (Median) | -1-43 (14.0) | -13-26 (12.0) | ||||
| Bone Conduction Hearing Acquisition | Mean ± SD | 29 | 1.8 ± 4.68 | 15 | 2.96 ± 4.3 | a 0.412 |
| Min-Max (Median) | -8-15 (2.0) | -4-10 (3.0) | ||||
| Gap Hearing Gain | Mean ± SD | 29 | 14.95 ± 9.79 | 15 | 8.18 ± 9.15 | a 0.045* |
| Min-Max (Median) | -2-36 (14.0) | -12-23 (9.5) | ||||
a Mann Whitney U Test *p < 0.05
Table 7.
Relationship between Eustachian tube function (ETF) and mastoid pneumatization
| Direction of Disease | |||
|---|---|---|---|
| Eustachian Tube Function | Unilateral (n 29) |
Bilateral (n 15) |
p |
| Normal | 11 | 6 | a 1 |
| Dysfunction | 18 | 9 | |
a Fisher exact Test
The preop gap value in cases with reduced mastoid pneumatization was found to be statistically significantly higher than in cases with normal mastoid pneumatization (p = 0.042; p < 0.05).
The preoperative airway value of the cases with reduced mastoid pneumatization was found to be remarkably higher than the cases with normal mastoid pneumatization, although it was not statistically significant (p = 0.083; p > 0.05).
No statistically significant difference was found between the airway, bone conduction and gap hearing gains of the cases according to mastoid pneumatization (p > 0.05).
No statistically significant difference was found between the airway and bone conduction hearing gains of the cases according to the direction of the disease (p > 0.05).
The gap airway gains of the cases with unilateral disease direction were found to be statistically significantly higher than those with bilateral disease direction (p = 0.045; p < 0.05).
Patients with unilateral involvement; ETF was found to be normal in 11 of them and dysfunctional in 18 of them. Patients with bilateral involvement; ETF was found to be normal in 6 of them and dysfunctional in 9 of them.
Statistical Reviews
NCSS (Number Cruncher Statistical System) 2007 (Kaysville, Utah, USA) program was used for statistical analysis. While evaluating the study data, in addition to descriptive statistical methods (mean, standard deviation, median, frequency, ratio, minimum, maximum) in the comparison of quantitative data, the Mann Whitney U test was used to compare two groups of variables that did not show normal distribution. Significance was evaluated at p < 0.01 and p < 0.05 levels.
Discussion
Tympanic membrane perforation is a frequent occurrence in the otolaryngology clinic. Type 1 tympanoplasty is performed to close the tympanic membrane perforation, get rid of an infection, and restore hearing. The success of type 1 tympanoplasty depends on many factors such as type of graft, type of approach, type of graft placement, eustachian tube function, condition of middle ear mucosa, middle ear ventilation, clearance of disease [1–5].
It is known that there is a relationship between mastoid pneumatization and ear diseases, and there are studies in the literature on genetic and environmental theories on the development of pneumatization [1, 9]. According to the genetic theory; the development of the mastoid cell system is under genetic control, and it is argued that the risk of middle ear infection increases in cases with low mastoid pneumatization. In environmental theory, it is suggested that normal mastoid pneumatization can only occur in the presence of healthy mucosa [10, 11].
In order to achieve successful hearing results in tympanoplasty, a well ventilated middle ear is needed. Eustachian tube dysfunction is often cited as a factor that causes insufficient ventilation of the middle ear after tympanoplasty [9]. It is suggested that the pneumatization of the mastoid bone is important in preventing the formation of retraction pouches and adequate aeration in the middle ear. In addition, it is accepted that there is a relationship between the degree of mastoid pneumatization and bilateral disease and Eustachian tube dysfunction.
In cases with Eustachian dysfunction, in cases with chronic middle ear disease who had frequent upper respiratory tract infections in childhood and had frequent otitis media, mastoid pneumatization decreases, the tegmen level is displaced inferiorly, towards the sigmoid sinus, and it tends to narrow the mastoid cavity [12]. There are studies in the literature on the relationship between ET functions and the success of tympanoplasty [13–15]. In their review investigating the role of mastoidectomy in chronic otitis media without cholesteatoma, Eliades and Limb concluded that mastoidectomy did not provide any additional benefit in uncomplicated tympanoplasty cases [13]. Mohammed Abdel Tawab et al., in their recently published study, they performed only myringoplasty in 20 patients with uncomplicated tympanic membrane perforation, and performed cortical mastoidectomy in addition to 20 patients and did not obtain a significant result between the two groups in terms of graft success and hearing results [14]. Yemin et al., found that the degree of mastoid pneumatization did not affect the success rate of type 1 tympanoplasty [15]. ElBeltagy et al., in their study in which they examined the effect of pneumatized and non- pneumatized mastoid on the success of tympanoplasty; found that mastoid pneumatization did not significantly affect the success rate of tympanoplasty [16]. In our study, we found significantly worse ET functions both in unilateral and bilateral disease, and this result is parallel with the studies in the literature regarding the role of Eustachian tube dysfunction in the development of COM (Table 7).
When we analyzed the results of type 1 tympanoplasty in uncomplicated, without cholesteatoma cases using the temporal bone computed tomography film and the direction of the disease in our study; we did not find a statistically significant difference between the airway, bone conduction and gap hearing gains of the cases according to the mastoid pneumatization status (p > 0.05). However, the preoperative gap value in cases with decreased mastoid pneumatization was found to be significantly higher than in cases with normal mastoid pneumatization (p = 0.042; p < 0.05). The results of our study show parallelism with the results of a small number of studies on this subject in the literature.
According to the direction of the disease (bilateral/unilateral); it was determined that the gap airway gains of the cases with unilateral disease direction were statistically significantly higher than those with bilateral disease direction (p = 0.045; p < 0.05).
Another result of the study is that mastoid pneumatization and lateralization of the disease do not have any effect on graft success.
These results show us that the degree of mastoid pneumatization is not a factor affecting the surgical success, but it is a negative indicator in terms of hearing function in the preoperative period, and the bilaterality of the disease adversely affects the surgical success in terms of hearing gain. In our study, both of the two cases in which the graft was perforated at the postoperative 6th month control had decreased mastoid pneumatization and the disease was followed bilaterally; this suggests the hypothesis that loss of mastoid pneumatization and bilateral involvement may affect the success of type 1 tympanoplasty.
The degree of mastoid pneumatization did not affect the success rate of temporal facia type 1 tympanoplasty. Further prospective studies with larger numbers of patients are needed to further evaluate the relationship between mastoid pneumatization and bilateral involvement and the success of tympanoplasty.
Authors’ contributions
Serhan Keskin: Study design, experimental applications, statistics, literature research, writing; Arzu Tatlipinar: Idea generation, study design, literature research, writing; Emrah Kinal: Experimental applications, idea generation, writing.
Funding
There is no funding/ financial support.
Declarations
Compliance with Ethical Standards
The authors assert that all procedures contributing to this work comply with the ethical standards of the relevant national and institutional guidelines on human experimentation and with the Helsinki Declaration of 1975, as revised in 2008.
Conflict of Interest
None.
Ethical Approval
The study protocol was approved by Local Ethical Committee before study.
Informed Consent
Written informed consent was obtained from all patients.
Footnotes
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
References
- 1.Akyıldız AN. Kulak Hastalıkları Ve Mikrocerrahisi. Ankara: Bilimsel Tıp Yayınevi; 1998. [Google Scholar]
- 2.Yazıcı H, Uzunkulaoğlu H, Emir HK, et al. Comparison of incus interpositioning technique versus glass ionomer cement application in type 2 tympanoplasty. Eur Arch Otorhinolaryngol. 2010;270:1593–1596. doi: 10.1007/s00405-012-2120-6. [DOI] [PubMed] [Google Scholar]
- 3.Aoki K, Esaki S, Honda Y, Tos M. Effect of middle ear Infection on pneumatization and growth of the mastoid process. An experimental study in pigs. Acta Otolaryngol. 1990;110:399–409. doi: 10.3109/00016489009107461. [DOI] [PubMed] [Google Scholar]
- 4.Austin DF. On the function of the mastoid. Otolaryngol Clin North Am. 1977;10:541–547. doi: 10.1016/S0030-6665(20)32595-0. [DOI] [PubMed] [Google Scholar]
- 5.Shatz A, Sade J. Correlation between mastoid pneumatization and position of the lateral sinus. Ann Otol Rhinol Laryngol. 1990;99:142–145. doi: 10.1177/000348949009900213. [DOI] [PubMed] [Google Scholar]
- 6.Stell PM. Scott-Brown’s otolaryngology. Vol. 3: management of chronic suppurative otitis media. 5. Oxford: Butterworth International; 1987. pp. 215–237. [Google Scholar]
- 7.Schilder AG, Bhutta MF, Butler CC, et al. Eustachian tube dysfunction: consensus statement on defi- nition, types, clinical presentation and diagnosis. Clin Otolaryngol Oct. 2015;40(5):407–411. doi: 10.1111/coa.12475. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Han SJ, Song MH, Kim J, Lee WS, Lee H-K. Classification of temporal bone pneumatization based on sigmoid sinus using computed tomography. Clin Radiol. 2007;62:1110–1118. doi: 10.1016/j.crad.2007.04.019. [DOI] [PubMed] [Google Scholar]
- 9.Sade J, Hadas E. Prognostic evaluation of secretory otitis media as a function of mastoidal pneumatization. Acta Otolaryngol. 1979;225:39–44. doi: 10.1007/BF00455874. [DOI] [PubMed] [Google Scholar]
- 10.Schwartz M (1966) Das Cholesteatom Im Gehörgang Und Im Mittelohr. Pathogenese, diagnose, Therapie Thime, Stutgart 795–796
- 11.Hug JE. A planimetric study of temporal bone pneumatization. Acta Otolaryngol. 1986;243:304–308. doi: 10.1007/BF00460206. [DOI] [PubMed] [Google Scholar]
- 12.Sirikci A, Bayazit YA, Kervancioğlu S, Ozer E, Kanlikama M, Bayram M. Assessment of mastoid air cell size versus sigmoid sinus variables with a tomography –assisted digital image processing program and morphometry. Surg Radiol Anat. 2004;26:145–148. doi: 10.1007/s00276-003-0201-3. [DOI] [PubMed] [Google Scholar]
- 13.Eliades SJ, Limb CJ. The role of mastoidectomy in outcomes following tympanic membrane repair: a review. Laryngoscope. 2013;123(7):1787–1802. doi: 10.1002/lary.23752. [DOI] [PubMed] [Google Scholar]
- 14.Mohammed Abdel Tawab H, Mahmoud Gharib F, Algarf TM, ElSharkawy LS. Myringoplasty with and without Cortical Mastoidectomy in treatment of non-cholesteatomatous chronic Otitis Media: a comparative study. Clin Med Insights Ear Nose Throat. 2014;12:19–23. doi: 10.4137/CMENT.S17980. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Yemin Y, Çelik M, Şimşek BM, et al. Impact of the degree of the mastoid pneumatization on cartilage type 1 Tympanoplasty Success. J Craniofac Surg Oct. 2016;27(7):e695–e698. doi: 10.1097/SCS.0000000000003022. [DOI] [PubMed] [Google Scholar]
- 16.ElBeltagy YM, Askoura AM, Hangal DEA, Teaima AA. Effect of pre-operative mastoid pneumatisation on tympanoplasty success. J Laryngol Otol Jun. 2022;136(6):500–504. doi: 10.1017/S0022215121004448. [DOI] [PubMed] [Google Scholar]